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Biomedical subjects

Akira Tamura

Publications and source records attributed to Akira Tamura.

At least 37 records · Page 2Linked to original sources
PubMed2005

Laparoscopic liver resection of hepatocellular carcinoma.

BACKGROUND: We have continued to develop laparoscopic hepatectomy as a means of surgical therapy for hepatocellular carcinoma (HCC). METHODS: We evaluated the degree of invasiveness and analyzed the outcomes of laparoscopic hepatectomy compared with open hepatectomy for HCC. RESULTS: There were notable differences with respect to blood loss and operating time compared with open hepatectomy cases. Patients started walking and eating significantly earlier in the laparoscopic hepatectomy group, and these more rapid recoveries allowed shorter hospitalizations. On the Estimation of Physiologic Ability and Surgical Stress (E-PASS) scoring system, there was no difference in preoperative risk. However, a significant difference was seen in the surgical stress and comprehensive risk scores between the open hepatectomy and laparoscopic hepatectomy groups. Concerning the survival rate and disease-free survival rate, there were no significant differences between procedures. CONCLUSIONS: Laparoscopic hepatectomy avoids some of the disadvantages of open hepatectomy and is beneficial for patient quality of life (QOL) as a minimally invasive procedure if the operative indications are appropriately based on preoperative liver function and the location and size of HCC.

Aged↗
PubMed2005

Pituitary apoplexy as a consequence of lymphocytic adenohypophysitis in a pregnant woman: a case report.

OBJECTIVE AND IMPORTANCE: A patient with pituitary apoplexy resulting from lymphocytic adenohypophysitis, which caused visual disturbance during pregnancy, is described. This is the first report of such case. CLINICAL PRESENTATION: A 23-year-old primigravida in her 25th week of gestation experienced headache and bitemporal hemianopsia of sudden onset. Magnetic resonance imaging (MRI) revealed a large pituitary mass with intratumoral hemorrhage. Although conservative treatment with intravenous glycerol improved the symptoms partially, the visual symptoms worsened again 6 weeks later. After delivering a girl by scheduled caesarean section her visual symptoms improved. Despite the symptomatic improvement, MRI showed the chiasmatic compression by the enlarged pituitary gland had not changed. Therefore, trans-sphenoidal surgery to decompress the chiasm was performed. Necrotic tissue was seen exuding behind the enlarged pituitary gland and adenohypophysitis with bleeding (apoplexy) was diagnosed histologically. After follow-up for 40 months, she was doing well without any visual or neurological deficits. CONCLUSION: Although relatively rare, pituitary apoplexy as a consequence of lymphocytic adenohypophysitis should be borne in mind when a pregnant woman presents with headache and visual disturbance of sudden onset.

Adult↗
PubMed2005

Naming of Rickettsiae and rickettsial diseases.

Over the last 20 years, advances in molecular techniques have greatly facilitated the identification of the members of the Rickettsiales, and numerous new species and diseases have been described. In this paper, we review taxonomic rules and appropriate approaches to valid naming of rickettsial species and the diseases they cause.

Animals↗
PubMed2005

Significance of neutrophil counts after reperfusion therapy in patients with a first anterior wall acute myocardial infarction.

BACKGROUND: Previous studies have demonstrated that an elevated neutrophil count on admission is associated with a higher risk of adverse events after acute myocardial infarction (AMI). However, the significance of the neutrophil count after reperfusion therapy has not been elucidated. METHODS AND RESULTS: The association of the neutrophil count on admission and days 2 and 3 with peak creatine kinase (CK) concentration, ST-segment resolution (a marker of myocardial tissue-level reperfusion), and left ventricular (LV) function at predischarge were examined in 122 patients (102 men, 20 women, mean age 61+/-11 years) with a first anterior wall AMI. Neutrophil counts were increased on day 2 and decreased on day 3 compared with admission (8,768+/-3,005 mm3, 6,617+/-2,424 mm3, and 7,725+/-3,388 mm3, respectively). Patients with ST-segment resolution (n=52) had lower neutrophil counts on days 2 and 3 than those without it (n=70), but neutrophil counts on admission did not differ significantly between patients with and without ST-segment resolution. Neutrophil counts on admission and days 2 and 3 were weakly but significantly correlated with peak CK concentration (r=0.31, p=0.0004; r=0.43, p<0.0001; r=0.32, p=0.003, respectively) and with LV ejection fraction at predischarge (r=-0.18, p=0.04; r=-0.26, p=0.003; r=-0.27, p=0.003; respectively). CONCLUSION: The neutrophil count after reperfusion is weakly but significantly correlated with infarct size, myocardial tissue-level reperfusion, and LV function at predischarge in a first anterior wall AMI. These correlations were slightly stronger than the correlations with the neutrophil count on admission.

Aged↗
PubMed2005

[Cryotherapy of the resection edge after hepatectomy of colorectal liver metastases].

Obtaining a one-centimeter negative margin is an important factor in preventing disease recurrence after surgery for hepatic tumors. Cryotherapy of the resected edge has been used to achieve optimal margin clearance in cases in which the alternative would be an extended high-risk liver resection. As a concrete method, cryotherapy was delivered with a liquid nitrogen based compact system (CRY-AC, Brymill Co., USA). The resection edge with involved or inadequate resection margins was ablated directly by using the flat probe for 3 minutes per 1 place. Between 2002 and present, a total of 14 patients with colorectal liver metastases underwent edge cryotherapy. Although there was no hemorrhage from the stump, postoperative leak of the bile and stump recurrence were recognized in each patient. Since cryotherapy has features that make the vascular difficult to be damaged, the complication was not recognized in the patient with exposed vascular in the resected edge. By extending the follow-up period, we want to examine whether the edge recurrence could be controlled or not.

Colorectal Neoplasms↗
PubMed2004

Endoplasmic reticulum stress and N-glycosylation modulate expression of WFS1 protein.

Mutations of the WFS1 gene are responsible for two hereditary diseases, Wolfram syndrome and low frequency sensorineural hearing loss. The WFS1 protein is a glycoprotein located in the endoplasmic reticulum (ER) membrane but its function is poorly understood. Herein we show WFS1 mRNA and protein levels in pancreatic islets to be increased with ER-stress inducers, thapsigargin and dithiothreitol. Another ER-stress inducer, the N-glycosylation inhibitor tunicamycin, also raised WFS1 mRNA but not protein levels. Site-directed mutagenesis showed both Asn-663 and Asn-748 to be N-glycosylated in mouse WFS1 protein. The glycosylation-defective WFS1 protein, in which Asn-663 and Asn-748 had been substituted with aspartate, exhibited an increased protein turnover rate. Consistent with this, the WFS1 protein was more rapidly degraded in the presence of tunicamycin. These data indicate that ER-stress and N-glycosylation play important roles in WFS1 expression and stability, and also suggest regulatory roles for this protein in ER-stress induced cell death.

Animals↗
PubMed2004

Circulating tenascin-C levels in patients with idiopathic dilated cardiomyopathy.

Circulating serum tenascin-C (an extracellular matrix glycoprotein) levels in patients with idiopathic dilated cardiomyopathy (IDC) were measured. Serum tenascin-C levels were increased in proportion to the severity of left ventricular dysfunction in patients with IDC. The associations of serum tenascin-C levels with serum troponin T and procollagen type III aminoterminal peptide levels suggest that increased levels of serum tenascin-C indicate ongoing replacement fibrosis after myocardial damage in IDC.

Aged↗
PubMed2004

In vivo influence of ceramide accumulation induced by treatment with a glucosylceramide synthase inhibitor on ischemic neuronal cell death.

It has been shown that exogenous ceramide induces delayed neuronal death (DND) of cultured hippocampal neurons. To evaluate the role of endogenous ceramide in ischemic DND, the glucosylceramide synthase inhibitor, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), was used to generate ceramide in gerbil hippocampi in vivo. The trimethylsilylated derivatives of ceramide were analyzed directly by gas chromatography mass spectrometry, after separation with high-performance thin-layer chromatography. The ceramide compositions in vehicle hippocampus consisted mainly of C18:0 fatty acyl sphingosine (87.9%), with C16:0 and C20:0 ceramides being minor components (7.1% and 5.1%, respectively). Ceramide level in the hippocampi from gerbils subjected to D-PDMP treatment was 1.5-fold higher than those from vehicle-treated gerbils. In spite of the accumulation of ceramide observed in the D-PDMP group, the histological studies did not reveal any ischemic neuronal death in hippocampal CA1 neurons with the gerbils that had been subjected to a sham operation (2-min sublethal ischemia). These results suggest that the ceramide accumulation induced by blocking the de novo synthesis of glucosylceramide with D-PDMP may be independent of the metabolic pathway underlying ischemic DND.

Animals↗
PubMed2004

Association of peripheral mononuclear cells containing Chlamydia pneumoniae DNA with acute coronary syndrome and stable coronary artery disease in Japanese subjects.

To clarify the association of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells (PBMCs) with acute coronary syndrome (ACS) and stable coronary artery disease (CAD) in Japanese adults, touchdown-nested polymerase chain reaction was used to detect the presence of C. pneumoniae DNA. The prevalence of C. pneumoniae DNA in PBMCs was similar in a comparison of 88 patients (52.3%) with ACS, 164 patients (50.0%) with stable CAD, and 88 control subjects (50.0%). Temporal changes in the prevalence of C. pneumoniae DNA in PBMCs were also assessed every 3 months during a 1-year period (n=59). The prevalence was significantly higher in the first 3-month period (January through March) than in any of the other 3-month periods. In conclusion, the prevalence of C. pneumoniae DNA in PBMCs in patients with ACS or stable CAD was comparable to that in control populations. Furthermore, the presence of circulating C. pneumoniae was strongly associated with seasonal variability.

Aged↗
PubMed2004

The leaf extract of Ginkgo Biloba L. suppresses oxidized LDL-stimulated fibronectin production through an antioxidant action in rat mesangial cells.

1 The leaf extract of Ginkgo Biloba L. exhibits a variety of pharmacological effects through an antioxidant action. We examined the effects of the leaf extract (Ginkgolon-24) on the production of fibronectin induced by oxidized low-density lipoprotein (oxLDL) in rat mesangial cells. 2 Stimulation with oxLDL accelerated the production of fibronectin with the preceding generation of reactive oxygen species (ROS). Pretreatment with Ginkgolon-24 inhibited the oxLDL-induced fibronectin production as well as ROS generation. 3 oxLDL also elicited the activation of SP-1, nuclear factor-kappaB, and cAMP response element-binding protein, which are transcription factors involved in the fibronectin production. Among these activated transcription factors, Ginkgolon-24 inhibited the activation of SP-1 only. 4 Furthermore, 7-ketocholesterol, an oxidized lipid in oxLDL particles, induced the production of fibronectin and the activation of SP-1, which were also suppressed by Ginkgolon-24. 5 These results suggest that the leaf extract of Ginkgo Biloba L. inhibits the oxLDL-induced production of fibronectin probably through inhibitory effects on ROS generation and SP-1 activation in rat mesangial cells.

Animals↗
PubMed2004

Blood pressure management in acute intracerebral hemorrhage: relationship between elevated blood pressure and hematoma enlargement.

BACKGROUND AND PURPOSE: The association between elevated blood pressure (BP) and hematoma enlargement in acute intracerebral hemorrhage (ICH) has not been clarified. We investigated the association between maximum systolic BP (SBP) and hematoma enlargement, measuring SBP between a baseline and a second CT scan in patients with hypertensive ICH. METHODS: We assessed 76 consecutive patients with hypertensive ICH retrospectively. We usually attempted to lower SBP below targets of 140, 150, or 160 mm Hg. Recordings of serial BP from admission until the second CT scan were assessed. A neuroradiologist, who was not informed of the aim of this study, reviewed CT films. Hematoma enlargement was defined as an increase in volume of > or =140% or 12.5 cm3. RESULTS: Hematoma enlargement occurred in 16 patients. Maximum SBP was significantly associated with hematoma enlargement (P=0.0074). A logistic regression model for predicting hematoma enlargement was constructed with the use of maximum SBP, hematoma volume, and Glasgow Coma Scale score at admission. After adjustment for these factors, maximum SBP was independently associated with hematoma enlargement (odds ratio per mm Hg, 1.04; 95% CI, 1.01 to 1.07). Target SBPs of > or =160 mm Hg were significantly associated with hematoma enlargement compared with those of < or =150 mm Hg (P=0.025). CONCLUSIONS: Our findings suggest that elevated BP increases the risk of hematoma enlargement. Efforts to lower SBP below 150 mm Hg may prevent this risk.

Acute Disease↗
PubMed2004

Disruption of the WFS1 gene in mice causes progressive beta-cell loss and impaired stimulus-secretion coupling in insulin secretion.

Wolfram syndrome, an autosomal recessive disorder characterized by juvenile-onset diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene. In order to gain insight into the pathophysiology of this disease, we disrupted the wfs1 gene in mice. The mutant mice developed glucose intolerance or overt diabetes due to insufficient insulin secretion in vivo. Islets isolated from mutant mice exhibited a decrease in insulin secretion in response to glucose. The defective insulin secretion was accompanied by reduced cellular calcium responses to the secretagogue. Immunohistochemical analyses with morphometry and measurement of whole-pancreas insulin content demonstrated progressive beta-cell loss in mutant mice, while the alpha-cell, which barely expresses WFS1 protein, was preserved. Furthermore, isolated islets from mutant mice exhibited increased apoptosis, as assessed by DNA fragment formation, at high concentration of glucose or with exposure to endoplasmic reticulum-stress inducers. These results strongly suggest that WFS1 protein plays an important role in both stimulus-secretion coupling for insulin exocytosis and maintenance of beta-cell mass, deterioration of which leads to impaired glucose homeostasis. These WFS1 mutant mice provide a valuable tool for understanding better the pathophysiology of Wolfram syndrome as well as WFS1 function.

Adenoviridae↗
PubMed2004

Hepatic resection using stapling devices.

BACKGROUND: The progress and development of stapling devices has been remarkable. They have become indispensable for gastrointestinal diseases and are increasingly utilized in laparoscopic operations. Liver surgery applications for this technique are continuing to emerge, and in this study, we introduced the use of stapling devices to hepatic surgery. METHODS: We examined the operative procedure and efficacy of hepatic resections using stapling devices as follows: transection of Glisson's pedicle and the hepatic vein using endolineal stapling devices in right and left lobectomies; bisegmentectomy II and III en masse using a stapling device; and application of endolineal stapling devices to vessel transections and dissections of the hepatic parenchyma in laparoscopic hepatectomies. RESULTS: It was considered useful to tactfully apply stapling devices to vessel transections and dissections of the hepatic parenchyma in order to simplify the operative procedures of right or left lobectomies and lateral segmentectomies. Furthermore, the use of endoscopic stapling devices was an acceptable alternative to vessel transactions and dissections of the hepatic parenchyma in laparoscopic hepatectomies. CONCLUSIONS: We believe that stapling devices will become utilized in liver surgery hereafter.

Hepatectomy↗
PubMed2004

Cerebrospinal fluid cytokines in Salmonella urbana encephalopathy.

We present a case report of encephalopathy associated with Salmonella urbana infection in a child. A 5-year-old boy was admitted to our clinic with convulsions and coma. Cerebrospinal fluid (CSF) interleukin-6 (IL-6) and IL-8 were elevated at onset and were decreased within normal limit on the fifth day. Residual neurological deficits included severe mental deficits and spastic tetraplegia. High levels of CSF proinflammatory cytokines might be related to central nervous system (CNS) disease activity. Although encephalopathy is a rare complication of non-typhi Salmonella infection, it should be borne in mind as an occasionally serious and potentially lethal disease.

Brain↗
PubMed2003

DNA fragmentation and detachment of enterocytes induced by anti-CD3 mAb-activated intraepithelial lymphocytes.

To elucidate the role of intraepithelial lymphocytes (IEL) and enterocytes in the defense mechanism of the small intestine, we designed experiments to stimulate the IEL by anti-CD3epsilon, anti-TCRalphabeta, or anti-TCRgammadelta monoclonal antibodies (mAbs), and to examine the subsequent changes to the enterocytes. The enterocytes of the duodenum and jejunum, but not of the ileum, showed massive DNA fragmentation 30 min after intraperitoneal injection of anti-CD3 mAb. These responses were also induced by anti-TCRgammadelta mAb, but not by anti-TCRalphabeta mAb, and were completely inhibited by cyclosporin A. Nearly half of the enterocytes of the villi in the duodenum and jejunum were exfoliated into the lumen 4 h after the injection of the mAb. Administration of anti-CD3 mAb also induced DNA fragmentation in Fas-deficient MRL/lpr mice, indicating that the Fas-Fas ligand system was not involved in these events. The anti-CD3 mAb treatment also induced massive DNA fragmentation in the intestinal epithelium of the duodenum and jejunum in TNF-receptor-1-deficient mice, whereas TNF-alpha induced only the detachment of intestinal epithelium of wild-type mice, implying the dissociation of two independent factors and/or mechanisms for DNA fragmentation and the subsequent epithelial cell detachment in the murine duodenum and jejunum. The mAb failed to exfoliate the epithelium in TNF-R1-deficient mice. Thus, TCRgammadelta(+) IEL, when treated with anti-CD3 or anti-TCRgammadelta mAbs, induced rapid DNA fragmentation and subsequent detachment of the duodenal and jejunal epithelia, but not in the ileum ("the silent ileum"), partly because of the paucity of TCRgammadelta(+) IELs in the ileum.

Animals↗